In a general process of butchering a poultry carcass, such as a chicken, into a meat portion and a bone portion, butchering, deboning, and removal of guts and the like (evisceration) are performed after feather removal and blood draining. Human labor cannot efficiently perform the butchering/deboning processing for poultry carcasses, and thus has been taken over by automated processes. For many years, the present applicants have been engaged in development of automatic deboning technique for a poultry carcass. The automatic deboning processing is executed for an upper body of a poultry carcass which is eviscerated and which has the leg portions and breast meat removed. Here, the poultry carcass is fixed on a conical fixing jig known as a “cone” to be in an appropriate posture during the entire deboning processing. In the processing, the poultry carcass in this state is subjected to the deboning processing executed by a plurality of processing units.
In the butchering/deboning processing, a poultry tenderloin extraction process is performed to extract poultry tenderloin from a poultry carcass which has had its wings and breast meat removed. The present applicants have developed an automatic deboning processing apparatus for an upper body of a poultry carcass, as described in Patent Document 1. FIG. 12 in Patent Document 1 illustrates poultry tenderloin extraction processing including: making incision on a portion between poultry tenderloin and a rib portion; then clasping the tendon at the front end of the poultry tenderloin with the front end of a chuck after pushing aside a collarbone; and then pulling the chuck to scrape off the poultry tenderloin.